Flexible tubing for hvac system

ABSTRACT

Embodiments of the present disclosure are directed toward a heating, ventilating, and air conditioning (HVAC) unit that includes a heat exchanger configured to establish a heat exchange relationship between a refrigerant flowing through a refrigerant loop of the HVAC unit and an air flow, where the heat exchanger has a refrigerant coil, a tubing segment configured to couple the refrigerant coil of the heat exchanger to another component of the HVAC unit, where the tubing segment has a flexible material, and a releasable connecting element, where the releasable connecting element is configured to couple the tubing segment to the heat exchanger.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/407,959, entitled “Use of Flexible Composite Tubing in Place of Rigid Copper Tubing in HVAC Equipment,” filed Oct. 13, 2016, and U.S. Provisional Patent Application No. 62/407,965, entitled “Use of Flexible Composite Tubing for Refrigerant Lines in Compressorized HVAC Equipment,” filed Oct. 13, 2016, which are hereby incorporated by reference in their entireties.

BACKGROUND

The present disclosure relates generally to environmental control systems, and more particularly, to tubing for a HVAC unit.

Environmental control systems are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. The environmental control system may control the environmental properties through control of an airflow delivered to the environment. For example, a heating, ventilating, and air conditioning (HVAC) system routes refrigerant through a heat exchanger and a compressor to exchange heat with the airflow and ultimately increase or decrease a temperature of the airflow. Tubing within the HVAC system directs the refrigerant to individual components of the HVAC system. In some cases, a large quantity of tubing is disposed within a relatively small area and the tubing is manipulated to conform to the provided space between components of the HVAC system. Traditionally, the tubing within the HVAC system includes a metallic material, such as copper. Unfortunately, copper is expensive and difficult to install because copper is relatively inflexible. Further, metallic fittings that couple the copper tubing with other components of the HVAC system further increase the costs of the HVAC system.

SUMMARY

In one embodiment, a heating, ventilating, and air conditioning (HVAC) unit that includes a heat exchanger configured to establish a heat exchange relationship between a refrigerant flowing through a refrigerant loop of the HVAC unit and an air flow, where the heat exchanger has a refrigerant coil, a tubing segment configured to couple the refrigerant coil of the heat exchanger to another component of the HVAC unit, where the tubing segment has a flexible material, and a releasable connecting element, where the releasable connecting element is configured to couple the tubing segment to the heat exchanger.

In another embodiment, a heat exchanger for a heating, ventilating, and air conditioning (HVAC) system includes a first coil configured to couple to a first releasable connecting element and a second coil configured to couple to a second releasable connecting element, where the first coil and the second coil are configured to be in fluid communication with one another via a tubing assembly. The tubing assembly includes a first tubing segment configured to couple to the first releasable connecting element at a first end of the first tubing segment and a first valve disposed at a second end of the first tubing segment, where the first valve is configured to be removably coupled to a second valve and a second tubing segment configured to couple to the second releasable connecting element at a third end of the second tubing segment, where the second valve is disposed at a fourth end of the second tubing segment.

In an another embodiment, a method of assembling a heat exchanger for a heating, ventilating, and air conditioning (HVAC) system includes coupling a first coil of the heat exchanger to a first releasable connecting element, coupling a second coil of the heat exchanger to a second releasable connecting element, coupling a first end of a first tubing segment to the first releasable connecting element, coupling a second end of a second tubing segment to the second releasable connecting element, and coupling a first valve of the first tubing segment to a second valve of the second tubing segment, where the first valve includes a first biasing member and the second valve includes a second biasing member, and where the first biasing member and the second biasing member are configured to adjust the first valve and the second valve, respectively, from a closed position to an open position when the first and second valves are coupled to one another.

DRAWINGS

FIG. 1 is a schematic of an environmental control for building environmental management that may employ one or more HVAC units, in accordance with an aspect of the present disclosure;

FIG. 2 is a perspective view of an embodiment of the environmental control system of FIG. 1, in accordance with an aspect of the present disclosure;

FIG. 3 is a schematic of a residential heating and cooling system, in accordance with an aspect of the present disclosure;

FIG. 4 is a schematic of an embodiment of a vapor compression system that can be used in any of the systems of FIGS. 1-3, in accordance with an aspect the present disclosure;

FIG. 5 is a perspective view of an embodiment of flexible tubing that may be used to couple components of the HVAC unit to one another, in accordance with an aspect of the present disclosure;

FIG. 6 is an exploded perspective view of an embodiment of a connecting element that may be utilized to attach the flexible tubing of FIG. 5 to inlet and outlet ports of the components of the HVAC unit, in accordance with an aspect of the present disclosure;

FIG. 7 is a schematic view of an embodiment of a heat exchanger system that may be utilized by the HVAC unit and includes the flexible tubing of FIG. 5 and the connecting element of FIG. 6, in accordance with an aspect of the present disclosure; and

FIG. 8 is a block diagram of an embodiment of a process for assembling the heat exchanger system of FIG. 7, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

The present disclosure is directed to heating, ventilating, and air conditioning (HVAC) systems that direct a refrigerant through a refrigerant loop. The refrigerant flows through tubing disposed between components of the HVAC system that facilitate heat transfer between an airflow and the refrigerant. Traditionally, tubing includes a metallic material, such as copper. However, copper is relatively expensive and may be difficult to manipulate to fit within an HVAC system. For example, to install copper tubing within a HVAC system, the tubing is adjusted and/or manipulated using machines and/or tools, and then welded or otherwise coupled to fittings that enable the tubing to be coupled to components of the HVAC system. Additionally, replacing segments of the metallic tubing may be difficult and/or time consuming because the tubing may be cut from corresponding fittings. Furthermore, in some cases it may be desirable to move and/or ship the HVAC system from one location to another. However, in HVAC systems that utilize metallic tubing, such as copper tubing, to couple, for example, coils of a heat exchanger, the refrigerant within the coils is drained before uncoupling the coils and is then refilled after transportation to a new location. As such, metallic tubing may increase time and costs of transporting HVAC systems because of the addition and removal of refrigerant during assembly and disassembly of heat exchangers.

Accordingly, embodiments of the present disclosure are directed to coupling components of an HVAC system using flexible tubing that facilitates assembly and reduces costs of the HVAC system, such as assembly costs and/or transportation costs. In some embodiments, the flexible tubing includes flexible composite tubing, such as a polymer inner layer and a metallic outer layer. The flexible tubing facilitates connections between components in the HVAC system compared to traditional copper tubing because the flexible tubing can couple without welding or using multiple fittings, resulting in quicker assembly and disassembly. For example, flexible tubing can be used to couple coils at a heat exchanger to one another. When also using valves with biasing members, the heat exchanger may be disassembled without having to drain the refrigerant inside the coils. For example, the biasing members of the valves adjust the valves to a closed position when disconnected from one another, thereby blocking fluid from flowing out of the coils.

Turning now to the drawings, FIG. 1 illustrates a heating, ventilating, and air conditioning (HVAC) system for building environmental management that may employ one or more HVAC units. In the illustrated embodiment, a building 10 is air conditioned by a system that includes an HVAC unit 12. The building 10 may be a commercial structure or a residential structure. As shown, the HVAC unit 12 is disposed on the roof of the building 10; however, the HVAC unit 12 may be located in other equipment rooms or areas adjacent the building 10. The HVAC unit 12 may be a single package unit containing other equipment, such as a blower, integrated air handler, and/or auxiliary heating unit. In other embodiments, the HVAC unit 12 may be part of a split HVAC system, such as the system shown in FIG. 3, which includes an outdoor HVAC unit 58 and an indoor HVAC unit 56.

The HVAC unit 12 is an air cooled device that implements a refrigeration cycle to provide conditioned air to the building 10. Specifically, the HVAC unit 12 may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow is supplied to the building. In the illustrated embodiment, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow from the building 10. After the HVAC unit 12 conditions the air, the air is supplied to the building 10 via ductwork 14 extending throughout the building 10 from the HVAC unit 12. For example, the ductwork 14 may extend to various individual floors or other sections of the building 10. In certain embodiments, the HVAC unit 12 may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other embodiments, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream.

A control device 16, one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device 16 also may be used to control the flow of air through the ductwork 14. For example, the control device 16 may be used to regulate operation of one or more components of the HVAC unit 12 or other components, such as dampers and fans, within the building 10 that may control flow of air through and/or from the ductwork 14. In some embodiments, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the supply air, return air, and so forth. Moreover, the control device 16 may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building 10.

FIG. 2 is a perspective view of an embodiment of the HVAC unit 12. In the illustrated embodiment, the HVAC unit 12 is a single package unit that may include one or more independent refrigeration circuits and components that are tested, charged, wired, piped, and ready for installation. The HVAC unit 12 may provide a variety of heating and/or cooling functions, such as cooling only, heating only, cooling with electric heat, cooling with dehumidification, cooling with gas heat, or cooling with a heat pump. As described above, the HVAC unit 12 may directly cool and/or heat an air stream provided to the building 10 to condition a space in the building 10.

As shown in the illustrated embodiment of FIG. 2, a cabinet 24 encloses the HVAC unit 12 and provides structural support and protection to the internal components from environmental and other contaminants. In some embodiments, the cabinet 24 may be constructed of galvanized steel and insulated with aluminum foil faced insulation. Rails 26 may be joined to the bottom perimeter of the cabinet 24 and provide a foundation for the HVAC unit 12. In certain embodiments, the rails 26 may provide access for a forklift and/or overhead rigging to facilitate installation and/or removal of the HVAC unit 12. In some embodiments, the rails 26 may fit into “curbs” on the roof to enable the HVAC unit 12 to provide air to the ductwork 14 from the bottom of the HVAC unit 12 while blocking elements such as rain from leaking into the building 10.

The HVAC unit 12 includes heat exchangers 28 and 30 in fluid communication with one or more refrigeration circuits. Tubes within the heat exchangers 28 and 30 may circulate refrigerant (for example, R-410A, steam, or water) through the heat exchangers 28 and 30. The tubes may be of various types, such as multichannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers 28 and 30 may implement a thermal cycle in which the refrigerant undergoes phase changes and/or temperature changes as it flows through the heat exchangers 28 and 30 to produce heated and/or cooled air. For example, the heat exchanger 28 may function as a condenser where heat is released from the refrigerant to ambient air, and the heat exchanger 30 may function as an evaporator where the refrigerant absorbs heat to cool an air stream. In other embodiments, the HVAC unit 12 may operate in a heat pump mode where the roles of the heat exchangers 28 and 30 may be reversed. That is, the heat exchanger 28 may function as an evaporator and the heat exchanger 30 may function as a condenser. In further embodiments, the HVAC unit 12 may include a furnace for heating the air stream that is supplied to the building 10. While the illustrated embodiment of FIG. 2 shows the HVAC unit 12 having two of the heat exchangers 28 and 30, in other embodiments, the HVAC unit 12 may include one heat exchanger or more than two heat exchangers.

The heat exchanger 30 is located within a compartment 31 that separates the heat exchanger 30 from the heat exchanger 28. Fans 32 draw air from the environment through the heat exchanger 28. Air may be heated and/or cooled as the air flows through the heat exchanger 28 before being released back to the environment surrounding the rooftop unit 12. A blower assembly 34, powered by a motor 36, draws air through the heat exchanger 30 to heat or cool the air. The heated or cooled air may be directed to the building 10 by the ductwork 14, which may be connected to the HVAC unit 12. Before flowing through the heat exchanger 30, the conditioned air flows through one or more filters 38 that may remove particulates and contaminants from the air. In certain embodiments, the filters 38 may be disposed on the air intake side of the heat exchanger 30 to prevent contaminants from contacting the heat exchanger 30.

The HVAC unit 12 also may include other equipment for implementing the thermal cycle. Compressors 42 increase the pressure and temperature of the refrigerant before the refrigerant enters the heat exchanger 28. The compressors 42 may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors 42 may include a pair of hermetic direct drive compressors arranged in a dual stage configuration 44. However, in other embodiments, any number of the compressors 42 may be provided to achieve various stages of heating and/or cooling. As may be appreciated, additional equipment and devices may be included in the HVAC unit 12, such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things.

The HVAC unit 12 may receive power through a terminal block 46. For example, a high voltage power source may be connected to the terminal block 46 to power the equipment. The operation of the HVAC unit 12 may be governed or regulated by a control board 48. The control board 48 may include control circuitry connected to a thermostat, sensors, and alarms (one or more being referred to herein separately or collectively as the control device 16). The control circuitry may be configured to control operation of the equipment, provide alarms, and monitor safety switches. Wiring 49 may connect the control board 48 and the terminal block 46 to the equipment of the HVAC unit 12.

FIG. 3 illustrates a residential heating and cooling system 50, also in accordance with present techniques. The residential heating and cooling system 50 may provide heated and cooled air to a residential structure, as well as provide outside air for ventilation and provide improved indoor air quality (IAQ) through devices such as ultraviolet lights and air filters. In the illustrated embodiment, the residential heating and cooling system 50 is a split HVAC system. In general, a residence 52 conditioned by a split HVAC system may include refrigerant conduits 54 that operatively couple the indoor unit 56 to the outdoor unit 58. The indoor unit 56 may be positioned in a utility room, an attic, a basement, and so forth. The outdoor unit 58 is typically situated adjacent to a side of residence 52 and is covered by a shroud to protect the system components and to prevent leaves and other debris or contaminants from entering the unit. The refrigerant conduits 54 transfer refrigerant between the indoor unit 56 and the outdoor unit 58, typically transferring primarily liquid refrigerant in one direction and primarily vaporized refrigerant in an opposite direction.

When the system shown in FIG. 3 is operating as an air conditioner, a heat exchanger 60 in the outdoor unit 58 serves as a condenser for re-condensing vaporized refrigerant flowing from the indoor unit 56 to the outdoor unit 58 via one of the refrigerant conduits 54. In these applications, a heat exchanger 62 of the indoor unit functions as an evaporator. Specifically, the heat exchanger 62 receives liquid refrigerant (which may be expanded by an expansion device, not shown) and evaporates the refrigerant before returning it to the outdoor unit 58.

The outdoor unit 58 draws environmental air through the heat exchanger 60 using a fan 64 and expels the air above the outdoor unit 58. When operating as an air conditioner, the air is heated by the heat exchanger 60 within the outdoor unit 58 and exits the unit at a temperature higher than it entered. The indoor unit 56 includes a blower or fan 66 that directs air through or across the indoor heat exchanger 62, where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork 68 that directs the air to the residence 52. The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence 52 is higher than the set point on the thermostat (plus a small amount), the residential heating and cooling system 50 may become operative to refrigerate additional air for circulation through the residence 52. When the temperature reaches the set point (minus a small amount), the residential heating and cooling system 50 may stop the refrigeration cycle temporarily.

The residential heating and cooling system 50 may also operate as a heat pump. When operating as a heat pump, the roles of heat exchangers 60 and 62 are reversed. That is, the heat exchanger 60 of the outdoor unit 58 will serve as an evaporator to evaporate refrigerant and thereby cool air entering the outdoor unit 58 as the air passes over the outdoor heat exchanger 60. The indoor heat exchanger 62 will receive a stream of air blown over it and will heat the air by condensing the refrigerant.

In some embodiments, the indoor unit 56 may include a furnace system 70. For example, the indoor unit 56 may include the furnace system 70 when the residential heating and cooling system 50 is not configured to operate as a heat pump. The furnace system 70 may include a burner assembly and heat exchanger, among other components, inside the indoor unit 56. Fuel is provided to the burner assembly of the furnace 70 where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger (that is, separate from heat exchanger 62), such that air directed by the blower 66 passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system 70 to the ductwork 68 for heating the residence 52.

FIG. 4 is an embodiment of a vapor compression system 72 that can be used in any of the systems described above. The vapor compression system 72 may circulate a refrigerant through a circuit starting with a compressor 74. The circuit may also include a condenser 76, an expansion valve(s) or device(s) 78, and an evaporator 80. The vapor compression system 72 may further include a control panel 82 that has an analog to digital (A/D) converter 84, a microprocessor 86, a non-volatile memory 88, and/or an interface board 90. The control panel 82 and its components may function to regulate operation of the vapor compression system 72 based on feedback from an operator, from sensors of the vapor compression system 72 that detect operating conditions, and so forth.

In some embodiments, the vapor compression system 72 may use one or more of a variable speed drive (VSDs) 92, a motor 94, the compressor 74, the condenser 76, the expansion valve or device 78, and/or the evaporator 80. The motor 94 may drive the compressor 74 and may be powered by the variable speed drive (VSD) 92. The VSD 92 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 94. In other embodiments, the motor 94 may be powered directly from an AC or direct current (DC) power source. The motor 94 may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

The compressor 74 compresses a refrigerant vapor and delivers the vapor to the condenser 76 through a discharge passage. In some embodiments, the compressor 74 may be a centrifugal compressor. The refrigerant vapor delivered by the compressor 74 to the condenser 76 may transfer heat to a fluid passing across the condenser 76, such as ambient or environmental air 96. The refrigerant vapor may condense to a refrigerant liquid in the condenser 76 as a result of thermal heat transfer with the environmental air 96. The liquid refrigerant from the condenser 76 may flow through the expansion device 78 to the evaporator 80.

The liquid refrigerant delivered to the evaporator 80 may absorb heat from another air stream, such as a supply air stream 98 provided to the building 10 or the residence 52. For example, the supply air stream 98 may include ambient or environmental air, return air from a building, or a combination of the two. The liquid refrigerant in the evaporator 80 may undergo a phase change from the liquid refrigerant to a refrigerant vapor. In this manner, the evaporator 38 may reduce the temperature of the supply air stream 98 via thermal heat transfer with the refrigerant. Thereafter, the vapor refrigerant exits the evaporator 80 and returns to the compressor 74 by a suction line to complete the cycle.

In some embodiments, the vapor compression system 72 may further include a reheat coil in addition to the evaporator 80. For example, the reheat coil may be positioned downstream of the evaporator relative to the supply air stream 98 and may reheat the supply air stream 98 when the supply air stream 98 is overcooled to remove humidity from the supply air stream 98 before the supply air stream 98 is directed to the building 10 or the residence 52.

It should be appreciated that any of the features described herein may be incorporated with the HVAC unit 12, the residential heating and cooling system 50, or other HVAC systems. Additionally, while the features disclosed herein are described in the context of embodiments that directly heat and cool a supply air stream provided to a building or other load, embodiments of the present disclosure may be applicable to other HVAC systems as well. For example, the features described herein may be applied to mechanical cooling systems, free cooling systems, chiller systems, or other heat pump or refrigeration applications.

As set forth above, embodiments of the present disclosure are directed to the HVAC unit 12 having flexible tubing that is utilized to couple components within the HVAC unit 12 to one another, such that a refrigerant flows through and between the components. For example, the flexible tubing may couple to an inlet part of a condenser, such as a heat exchanger having a set of condenser coils, to enable the refrigerant to flow from the compressor to the condenser. Further, the flexible tubing may couple an indoor unit to an outdoor unit. As such, the refrigerant conduits 54 of FIG. 3 may include the flexible tubing. The flexible tubing may also couple internal segments and/or portions within an individual component of the HVAC unit 12. For example, a condenser of the HVAC unit 12 may include multiple coils. Accordingly, the flexible tubing may be used to couple a first coil of the condenser to a second coil of the condenser to enable the refrigerant to flow through and between both the first coil and the second coil of the condenser. Indeed, the flexible tubing disclosed herein may be utilized to couple many of the components discussed above with reference to FIGS. 1-3 above. The flexible tubing facilitates manufacturing and/or assembly of the HVAC unit 12 and reduces costs of the HVAC unit 12 when compared to existing metallic tubing.

For example, FIG. 5 is a perspective view of an embodiment of a segment of flexible tubing 100 that may be used in the HVAC unit 12. As shown in the illustrated embodiment of FIG. 5, the flexible tubing 100 includes a first layer 102, such as a first annular sleeve having a first material, disposed around a second layer 104, such as a second annular sleeve having a second material. A refrigerant flows through a passage 107 of the second layer 104, which is sealed to block the refrigerant fluid from leaking out of the flexible tubing 100. In some embodiments, the flexible tubing 100 includes a reinforcement layer 106, such as a third annular sleeve having a third material. The reinforcement layer 106 may increase a strength or robustness of the second layer 104 to reduce fracturing and/or other wear that may be experienced by the second layer 104 and may also facilitate sealing and/or blocking refrigerant from leaking out of the flexible tubing 100. In some embodiments, a third material of the reinforcement layer 106 may include carbon, glass, aramid, or any combination thereof. The second material of the second layer 104 may include polyethylene, nylon, polyvinyl chloride, polypropylene, another suitable polymeric material, or any combination thereof. Because the passage 107 of the second layer 104 may directly contact the refrigerant, the second material of the second layer 104 is resistant to, unreactive with, or inert with respect to the refrigerant. Thus, in some embodiments, selection of the second material is based on the composition of the refrigerant. The second material of the second layer 104 may thus reduce premature fracturing of the second layer 104 and prolong an operating lifespan of the flexible tubing 100.

The first layer 102 provides stability to the flexible tubing 100 to maintain a desired geometry and/or rigidness of the flexible tubing 100. For example, the second material of the second layer 104 may not enable the flexible tubing 100 to maintain the desired geometry and/or rigidness on its own. However, the first material of the first layer 102 may increase a rigidness of the flexible tubing 100, such that the flexible tubing 100 may maintain the desired geometry. Additionally, the first layer 102 of the flexible tubing 100 may provide support to the flexible tubing 100 against forces exerted on the flexible tubing 100 due to a flow of refrigerant, gravitational force, and/or other external forces applied to the HVAC unit 12. For example, the first layer 102 may absorb at least a portion of the forces applied to the flexible tubing 100, thereby reducing forces applied to the second layer 104. Further, a thickness 108 of the first layer 102 facilitates adjustment of a position of the flexible tubing 100 when compared to tubing that is formed from a rigid metal or plastic, such as copper tubing and/or polyvinyl chloride tubing. In some embodiments, the first layer 102 may form a coiled structure, which increases a flexibility of the flexible tubing 100 and enables adjustment of a position of the flexible tubing 100 without the use of machinery and/or tools while providing a predetermined amount of rigidness. The first material of the first layer 102 may be aluminum, carbon steel, stainless steel, another suitable metallic material, or any combination thereof. Accordingly, in some embodiments, the flexible tubing 100 is flexible composite tubing that has more than one material. In other words, the flexible tubing 100 may include a polymer material in the second layer 104 and a metallic material in the first layer 102. However, in other embodiments, the material of the first layer 102, the second layer 104, and/or the reinforcement layer 106 may be the same.

In some embodiments, the flexible tubing 100 is formed by coupling the second layer 104 and the first layer 102 to one another. For example, the first layer 102 and the second layer 104 may be coupled using an adhesive, a fastener, another suitable technique, or any combination thereof. In embodiments that couple the first layer 102 and the second layer 104 using an adhesive, the adhesive may include epoxy, resin, or any combination thereof.

In some embodiments, the flexible tubing 100 is used for coupling components of the HVAC unit 12 to one another. Additionally or alternatively, the flexible tubing 100 is used to fluidly couple the indoor HVAC unit 56 to the outdoor HVAC unit 58, such that the flexible tubing 100 is used as the refrigerant conduits 54 (see FIG. 3). Further, the flexible tubing 100 may be used to couple internal segments and/or portions within an individual component of the HVAC unit 12. As discussed above, fittings may be utilized to couple two pieces of metallic tubing to one another, which may enable the metallic tubing to change direction without utilizing a machine or tool to adjust position or orientation of the metallic tubing. However, a position of the flexible tubing 100 can be easily adjusted without fittings and/or tools. In other words, a single piece of the flexible tubing 100 is pliable and may be adjusted to achieve a desired configuration between components of the HVAC unit 12. As such, utilizing the flexible tubing 100 reduces a cost of the HVAC unit 12 by reducing and/or eliminating fittings between pieces of the flexible tubing 100. Additionally, the flexible tubing 100 reduces an assembly time of the HVAC unit 12 by enabling adjustment of the configuration of the flexible tubing 100 without machines and/or tools.

FIG. 6 illustrates an embodiment of a connecting element 120 that may be utilized to couple the flexible tubing 100 of FIG. 5 to a component in HVAC unit 12, such as the compressor 74, the condenser 76, the expansion device 78, the evaporator 80, and/or another suitable component. As shown in the illustrated embodiment of FIG. 6, segment 130 of the flexible tubing 100 may be disposed in the connecting element 120. The connecting element 120 may include an attachment point 122 at a first end 123 and an attachment point 124 at a second end 125. In some embodiments, the connecting element 120 couples the segment 130 of the flexible tubing 100 with another segment (not shown) of the flexible tubing 100. For example, the connecting element 120 may couple the segment 130 of the flexible tubing 100 having a first diameter with another segment of the flexible tubing 100 having a second diameter, where the second diameter is smaller or larger than the first diameter. In the illustrated embodiment of FIG. 6, the attachment point 122 of the connecting element 120 couples with an end 132 of the segment 130 of the flexible tubing 100 and the attachment point 124 of the connecting element 120 couples with an end of another segment of the flexible tubing 100. Further, in other embodiments, the connecting element 120 couples the segment 130 of the flexible tubing 100 with an inlet or outlet port of a component of the HVAC unit 12, such as the compressor 74, the condenser 76, the expansion device 78, and/or the evaporator 78. As such, the attachment point 122 may couple to the end 132 of the segment 130 of the flexible tubing 100, and the attachment point 124 may couple to the inlet or outlet port of the component of the HVAC unit 12 or vice versa.

The attachment points 122 and 124 may utilize the same or different mechanisms, such as releasable coupling mechanisms, to couple to the flexible tubing 100 and/or the inlet or outlet port of a component of the HVAC unit 12. The releasable coupling mechanisms may include components that couple via clamping, threading, interference fitting, friction fitting, interlocking, or other coupling mechanism. For example, in some embodiments, the attachment points 122 and 124 may include a clamp 133 to secure the connecting element 120 to the flexible tubing 100. The clamp 133 may be disposed about a passage 126 of the connecting element 120 and be configured to receive the flexible tubing 100, such that an outer circumference of the flexible tubing 100 is surrounded by the clamp 133 when the flexible tubing 100 is inserted into the passage 126 of the connecting element 120. In other embodiments, the attachment points 122 and 124 may attach to ends of the flexible tubing 100 and/or an inlet or outlet port of the component of the HVAC unit 12 via threads or other releasable coupling mechanism. In any case, the respective coupling mechanisms of attachment points 122 and 124 facilitate assembly of the HVAC unit 12 when compared to existing fittings and/or metallic tubing that may utilize welds or other permanent mechanical coupling to couple the tubing to one another and/or to a component of an HVAC system.

In addition, the clamp 133 and/or threads of the connecting element 120 form a seal to block refrigerant from leaking from the attachment points 122 and 124. In some embodiments, the connecting element 120 includes an intermediate portion 128 between the attachment point 122 and the attachment point 124. The intermediate portion 128 is also sealed to block refrigerant from leaking and may be any suitable length to facilitate a connection between the flexible tubing 100 and a component of the HVAC unit 12. Additionally, while the illustrated embodiment of FIG. 6 shows the attachment point 122 as having a circular cross-sectional shape and the attachment point 124 as having a rectangular cross-sectional shape, it should be understood that the attachment points 122 and 124 may include any suitable cross-sectional shape that enables coupling between segments of the flexible tubing 100 or the flexible tubing 100 and a component of the HVAC unit 12.

In some embodiments, the flexible tubing 100 is slidably disposed within the passages 126 of the connecting element 120 to couple the flexible tubing 100 to the connecting element 120. As such, refrigerant is configured to flow through the passage 126 of the connecting element 120 from the attachment point 122, through the intermediate portion 128, and toward the attachment point 124. As discussed above, the attachment point 122 includes the clamp 133, threads, or other coupling mechanism that secures the flexible tubing 100 within the connecting element 120. As should be understood, coupling the flexible tubing 100 to the connecting element 120 is faster when compared to welding, and uncoupling the flexible tubing 100 from connecting element 120 enables the flexible tubing 100 to be adjusted or reused.

FIG. 7 illustrates an embodiment of a heat exchanger 146, such as the condenser 76 and/or the evaporator 80 of the HVAC unit 12. The heat exchanger 146 includes a first coil 148 and a second coil 150. Refrigerant flows through the first and second coils 148 and 150, either in a series arrangement or in a parallel arrangement, and air is drawn over the coils 148 and 150 via a fan 151. As air comes into contact with the coils 148 and 150, thermal energy is exchanged between the air and the refrigerant flowing through the coils 148 and 150. In some embodiments, the coils 148 and 150 may transfer thermal energy to the air, thereby increasing the temperature of the air and in turn, decreasing a temperature of the refrigerant, such as when the coils 148 and 150 are coils of the condenser 76. In some embodiments, the coils 148 and 150 may absorb thermal energy from the air, thereby decreasing the temperature of the air and in turn, increasing the temperature of the refrigerant, such as when the coils 148 and 150 are coils of the evaporator 80.

As shown in the illustrated embodiment of FIG. 7, each of the coils 148 and 150 is coupled to respective connecting elements 155 and 157. The coils 148 and 150 may also be in fluid communication with each other via a tubing assembly 152. The tubing assembly 152 includes the segment 130 of flexible tubing 100, a second segment 153 of the flexible tubing 100, and valves 154. Each segment 130 and 153 of the flexible tubing 100 couples to a respective valve 154 at one end and the respective connecting element 155 or 157 at the other end. Further, the valves 154 are configured to couple with one another. In some embodiments, the valves 154 each include a biasing member 156, such as a spring, that is configured to adjust the valves 154 from an open position to a closed position. As should be understood, in the open position, the valves 154 permit refrigerant to flow through the valves 154 and between the segments 130 and 153 of the flexible tubing 100. In the closed position, the valves 154 block refrigerant from flowing through the valves 154 and between the segments 130 and 153 of the flexible tubing 100. The biasing member 156 may include a spring loaded mechanism that adjusts a position of the valves 154 between the open position and the closed position.

Accordingly, in some embodiments, the valves 154 are in the open position when coupled to one another. In some embodiments, the valves 154 use genderless connectors that include spring activated gates, such that upon connection with a corresponding valve 154, a spring is pushed back to open the gate. When the valves 154 are coupled to one another, the biasing members 156 of the valves 154 engage one another, thereby applying a force that opposes a biasing force of the biasing members 156. As such, the valves 154 move from the closed position to the open position when coupled to one another. Additionally, the valves 154 are in the closed position when uncoupled from one another. For example, the biasing members 156 of the valves 154 no longer engage one another, such that the force opposing the biasing force of the biasing members 156 is removed. The biasing members 156 thus cause the valves 154 to move from the open position to the closed position as valves 154 are decoupled from one another.

Accordingly, when the valves 154 of the tubing assembly 152 are coupled to one another, refrigerant flows between the coils 148 and 150. Likewise, when the valves 154 of the tubing assembly 152 are not coupled to one another, refrigerant flow between the coils 148 and 150 is blocked. The tubing assembly 152 thus enables the heat exchanger 146 to be disassembled and transported without discharging the refrigerant from the coils 148 and 150. Coupling the segments 130 and 153 of the flexible tubing 100 with the valves 154 may be performed by disposing the clamp 133 into an opening of the valves 154 to secure the flexible tubing 100 within the valves 154. In other embodiments, the valves 154 may be coupled to the segments 130 and 153 of the flexible tubing 100 using threads, a jaw couple, a quick disconnect, another suitable releasable coupling mechanism, or any combination thereof.

As shown in the illustrated embodiment of FIG. 7, the coils 148 and 150 are positioned to form an angle 158 with respect to one another. In some embodiments, the angle 158 is approximately, such as within 10% of, 90 degrees. In other embodiments, the angle 158 is between 45 degrees and 120 degrees, between 50 degrees and 110 degrees, or between 60 degrees and 100 degrees. In any case, the angle 158 formed between the coils 148 and 150 provides relatively large surface area for the air to contact the coils 148 and 150, but reduces an amount of space consumed by the coils 148 and 150. In other words, the amount of space consumed by the coils 148 and 150 is reduced when compared to coils 148 and 150 being positioned at an angle of 180 degrees with respect to one another. Additionally, the angle 158 may be adjustable by virtue of the coupling of the coils 148 and 150 with the tubing assembly 152. That is, use of flexible tubing described herein with the tubing assembly 152 may enable the tubing assembly 152 to be flexible or adjustable to thereby adjust the relative positions, such as the angle 158, of the coils 148 and 150 with respect to one another.

FIG. 8 is a flow chart of an embodiment of a process 168 for manufacturing the heat exchanger 146 of FIG. 7. For example, at block 170, the coil 148 is coupled to the first connecting element 155. At block 180, the coil 150 is coupled to the second connecting element 157. As discussed above, the connecting elements 155 and 157 may couple to an inlet or outlet port of the coils 148 and 150 via threads, the clamp 133, or other coupling mechanism, such as a releasable coupling mechanism. At block 190, the first end of the segment 130 is coupled to the first connecting element 155. The second end of the segment 130 is coupled to the valve 154. At block 200, the first end of the segment 153 is coupled to the first connecting element 155. The second end of the segment 153 is coupled to another valve 154. The segments 130 and 153 of the flexible tubing 100 may be coupled and secured to the respective connecting elements 155 and 157 via the clamp 133 or other coupling mechanism. In block 210, the two valves 154 are coupled to one another using threads, a jaw couple, a quick disconnect, other coupling mechanism, or any combination thereof.

When the valves 154 are coupled to one another, the biasing members 156 in each of the valves 154 cause the valves 154 to be in the open position, which enables refrigerant to flow through the valves 154 and between the coils 148 and 150. Additionally, when the valves 154 are not coupled to one another, the biasing members 156 in each valve 154 cause the valves 154 to be in the closed position, which blocks refrigerant from flowing through the valves 154 and between the coils 148 and 150. Therefore, the heat exchanger 146 having the coils 148 and 150 may be disassembled and transported without discharging the refrigerant from the coils 148 and 150. Similarly, the heat exchanger 146 may be assembled (or reassembled) without recharging the coils 148 and 150. As such, assembling and disassembling heat exchangers, such as to ship parts of the HVAC unit 12 is facilitated by using the flexible tubing 100, the connecting elements 120, and/or the valves 154.

As set forth above, embodiments of the flexible tubing of the present disclosure may provide one or more technical effects useful in the assembly and/or disassembly of HVAC systems. For example, the flexible tubing may be utilized to couple components of a HVAC unit to one another. The flexible tubing may also couple segments and/or portions within an individual component of the HVAC unit. In any case, the flexible tubing may include a structure that enables the flexible tubing to be easily manipulated, thereby facilitating adjustment of the position of the flexible tubing. As such, a single segment of the flexible tubing may be utilized in place of multiple pieces of metallic tubing, thereby decreasing the cost of the HVAC unit. Furthermore, for heat exchangers in an HVAC unit that utilize multiple coils, an assembly having the flexible tubing may connect the coils to one another. Additionally, the assembly may include valves coupled to the flexible tubing, which enable when the valves are coupled to one another. When the valves are not coupled to one another, the valves may be adjusted to a closed position via a biasing mechanism, which blocks the flow of refrigerant between coils and encloses the refrigerant within the coils. Thus, the coils may be disassembled without discharging the refrigerant from the coils, thus saving time in transporting the HVAC unit from one location to another. The technical effects and technical problems in the specification are examples and are not limiting. It should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems.

While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode, or those unrelated to enablement). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation. 

1. A heating, ventilating, and air conditioning (HVAC) unit, comprising: a heat exchanger configured to establish a heat exchange relationship between a refrigerant flowing through a refrigerant loop of the HVAC unit and an air flow, wherein the heat exchanger comprises a refrigerant coil; a tubing segment configured to couple the refrigerant coil of the heat exchanger to another component of the HVAC unit, wherein the tubing segment comprises a flexible material; and a releasable connecting element, wherein the releasable connecting element is configured to couple the tubing segment to the heat exchanger.
 2. The HVAC unit of claim 1, wherein the tubing segment is a first tubing segment, the releasable connecting element is a first releasable connecting element, the refrigerant coil is a first refrigerant coil, the first releasable connecting element is configured to couple the first tubing segment to the first refrigerant coil of the heat exchanger, and the HVAC unit comprises: a second refrigerant coil of the heat exchanger; a second tubing segment configured to couple to the second refrigerant coil; and a second releasable connecting element configured to couple the second tubing segment to the second refrigerant coil, wherein the first and second tubing segments are configured to couple to one another via a first valve of the first tubing segment and a second valve of the second tubing segment.
 3. The HVAC unit of claim 2, wherein the first valve comprises a first biasing member and the second valve comprises a second biasing member, wherein the first biasing member and the second biasing member are configured to adjust the first valve and the second valve, respectively, from an open position to a closed position.
 4. The HVAC unit of claim 3, wherein the first biasing member and the second biasing member each comprises a spring loaded mechanism.
 5. The HVAC unit of claim 3, wherein the first valve and the second valve are both in the open position when the first valve and the second valve are coupled to one another.
 6. The HVAC unit of claim 5, wherein the refrigerant is configured to flow through the first valve and the second valve when the first valve and the second valve are both in the open position.
 7. The HVAC unit of claim 3, wherein the first valve and the second valve are both in the closed position when the first valve and the second valve are decoupled from one another.
 8. The HVAC unit of claim 2, wherein the first refrigerant coil and the second refrigerant coil are positioned to form an angle between 0 degrees and 90 degrees with respect to one another, wherein the angle is adjustable when the first refrigerant coil and the second refrigerant coil are coupled to one another via the first and second tubing segments.
 9. The HVAC unit of claim 2, wherein the first releasable connecting element and the second releasable connecting element each comprises threads.
 10. The HVAC unit of claim 1, wherein the refrigerant coil comprises a condenser coil.
 11. The HVAC unit of claim 1, wherein the tubing segment comprises a metal layer and a polymer layer.
 12. The HVAC unit of claim 11, wherein the metal layer comprises aluminum, carbon steel, stainless steel, or any combination thereof.
 13. The HVAC unit of claim 11, wherein the polymer layer comprises polyethylene, nylon, polyvinyl chloride, polypropylene, or any combination thereof.
 14. The HVAC unit of claim 1, wherein the releasable connecting element comprises a clamp to couple the tubing segment to the heat exchanger.
 15. The HVAC unit of claim 14, wherein the clamp is disposed about a central passage of the releasable connecting element.
 16. The HVAC unit of claim 14, wherein the clamp is configured to secure the tubing segment to the connecting element by surrounding an outer circumference of the tubing segment.
 17. A heat exchanger for a heating, ventilating, and air conditioning (HVAC) system, comprising: a first coil configured to couple to a first releasable connecting element; and a second coil configured to couple to a second releasable connecting element, wherein the first coil and the second coil are configured to be in fluid communication with one another via a tubing assembly, wherein the tubing assembly comprises: a first tubing segment configured to couple to the first releasable connecting element at a first end of the first tubing segment and a first valve disposed at a second end of the first tubing segment, wherein the first valve is configured to be removably coupled to a second valve; and a second tubing segment configured to couple to the second releasable connecting element at a third end of the second tubing segment, wherein the second valve is disposed at a fourth end of the second tubing segment.
 18. The heat exchanger of claim 17, wherein the first valve and the second valve each comprises a biasing member to adjust the first valve and the second valve from an open position to a closed position, and wherein the first valve and the second valve are each configured to be in the open position when the first valve and the second valve are coupled to one another and are each configured to be in the closed position when the first valve and the second valve are decoupled from one another.
 19. The heat exchanger of claim 18, wherein the first releasable connecting element and the second releasable connecting element each comprises a clamp configured to couple to the first tubing segment and the second tubing segment, respectively, and wherein the clamp is disposed about a central passage on the respective first and second connecting elements.
 20. The HVAC unit of claim 18, wherein the first tubing segment, or the second tubing segment, or both comprises a metal layer and a polymer layer.
 21. A method of assembling a heat exchanger for a heating, ventilating, and air conditioning (HVAC) system, comprising: coupling a first coil of the heat exchanger to a first releasable connecting element; coupling a second coil of the heat exchanger to a second releasable connecting element; coupling a first end of a first tubing segment to the first releasable connecting element; coupling a second end of a second tubing segment to the second releasable connecting element; and coupling a first valve of the first tubing segment to a second valve of the second tubing segment, wherein the first valve comprises a first biasing member and the second valve comprises a second biasing member, and wherein the first biasing member and the second biasing member are configured to adjust the first valve and the second valve, respectively, from a closed position to an open position when the first and second valves are coupled to one another.
 22. The method of assembling the heat exchanger of claim 21, wherein the first valve is disposed at a third end of the first tubing segment opposite the first end, and the second valve is disposed at a fourth end of the second tubing segment opposite the second end.
 23. The method of assembling the heat exchanger of claim 21, comprising decoupling the first valve from the second valve to adjust the first valve and the second valve from the open position to the closed position.
 24. The method of assembling the heat exchanger of claim 21, wherein the first tubing segment comprises a first flexible material, and the second tubing segment comprises a second flexible material.
 25. The method of assembling the heat exchanger of claim 21, wherein the first releasable connecting element comprises a clamp, threads, a friction fit connector, an interference fit connector, and interlocking connector, or any combination thereof. 